raffish

Someone raffish is a bit of a scoundrel, carelessly making mischief. Your raffish classmate might constantly play mean practical jokes, always denying responsibility with a charming smile.

If you're raffish, you're a "rake" or a "cad." Though you're pretty much bad news, you pull off your dastardly deeds in an attractive manner. Someone with a raffish look is intriguing as well as disreputable. Raffish comes from riff-raff, "generally undesirable people," from the Medieval French rifle et rafle, "stealing from the bodies of the dead on the battlefield."